If $a + b = 5$ and $x + y = 9$, what is $-10y - 10x + 4a + 4b$ ?
$= 4a + 4b - 10x - 10y$ $= (4) \cdot (a + b) + (-10) \cdot (x + y)$ $= (4) \cdot (5) + (-10) \cdot (9)$ $= 20 - 90$ $= -70$